Method of treating lubricating-oil stocks



-lATNT ORE, CALIFORNIA, AND WILLIAM J. BYAILJE, OF SEATTLE I WASHINGTON.

WHO!) 01E TREATING LUBRICATiNG-OIL STOCKS.

No wing.

This invention relates to the step in the manufacture of lubricating oils of removing the salts or reaction products from a sulphuric acid' treated oil after neutraliza ing with an alkaline substance such as sodium hydromde, lime, soda ash or other substances of an alkaline nature.

In the treatment of lubricating distillat es for the manufacture of lubricating oils, m

to the step of neutralizing the acid remaining in the'oil after the sulphuric acid treatment with alkaline substances, salts or soaps are formed whichcombine with the oil in a state of emulsion and are very di flicult to 115 IGHJOVG.

We have discovered that these salts or soaps may be removed by treating the 011 with colloidal clay in a finely divided state under heat, and that they may be most so readily removed when only suflicient alkaline substance is applied in the neutralizing step to neutralizet e acid present without a substantial excess of alkaline substance. When the alkaline substanceis applied in proper quantity and net in excess of the quantity necessary to neutralize the acid bodies present; substantially no sedimentation takes place in its application. The reaction products between the alkaline substance and the acids present remain in suspension in the oil under treatment in the form of an emulsion.

We have discovered that in the step of neutralizing the acid bodies in the oil in this manner to cause the salts or soaps to emulsi with the oil under treatment, causing the salts or soaps to, be formed in this manner forms'them into compounds which may be readily extracted'with colloidal clays in a finely divided state.

Our discovery resides in the peculiar -method of creating and forming a salt or soap that may be readil extracted by treatment with finely divided colloidal clay. W m? we do not confine ourselves strictly thereto, the following is a preferred method of procedure in the carrying out of our process:

, Lubricatin oil stock is treated with sulhuric acid y any of the methods well to. in the art, after which the sludge feed in the acid treatment is, drawn ofi or removed. The sludge-free oil is then treated preierab with a strong solution of caustic soda, ii

cient only to neutralize the acid Application filed March 3, 1926. Serial No. 92,039%.

soda solution is applied, substantially no sedimentation will occur. The caustic soda solution, after combining with the acid bodies in the oil, will form an emulsion and remain suspended in the oil under treate well known ment. This'step isparticularly important,

and the reaction thus accomplished forms bodies inthe oil which may be readily removed by treatment with colloidal clay in a finely divided state, preferably of a fineness whereby 90% will pass through a200- mesh, screen.

Heretoforel i the soaps formed in the neutralizing of acid bodies in oil have been removed by washing with water, alcohol or other solvents. In our process we add-and agitate with the oil containing the salts or.

soaps in an emulsified state, finely divided colloidal clay in sufiicient quantity to remove the salts or soaps. This quantity will vary in direct ratio to the quantity of saltsjor soaps to be removed. Generally clay in pro portions of 5,000 gallons of oil to one ton of clay will be'suflicient, and in some cases a used intimate admixture in any suitable mixing or agitating apparatus, the oil is'heated by any suitable means to a proper temperature wherein the salts or soaps may be removed by the clay adsorption with any well known filtering apparatus or filter press. The temperature required is usually approximately 300 F., always above 212 F., and in some cases where the air is excluded much higher temperatures may be used, even u to temperatures just below the boiling point of the oil under treatment. In certain cases pressure may be found necessary while the oil is under heat to prevent foaming and for the removal of vapors evolved by the heat applied.

Finely divided adsorbent material as herein used is meant to include all substances having adsorptive properties, such as fullers earth, colloidal clay, bauxite, montmorillons a While the oil and clay are maintained in 'very much smaller quantity of, clay may be n al ll ite, yrophyllite, diatomaeeous earth, bone bl sihca-gel and all such substances. The adsorbent material may or may not have decolorizing properties; indeed,'many colloidal claysv found in California have adsorbent properties suflicient to remove soaps but substantially no decolorizing properties.

It is to be distinctly understood that this is not a decolorizing method; in fact, the salts or soaps herein removed destroy the decolorizing properties of adsorbent materials. However, the removal of the salts or soaps in this manner tends to stabilize the color obtained by the acid treatment.

The word soaps as herein used is meant to include the reaction products formed in neutralizing acid bodies with an alkaline substance, as the term is commonly used in the art of treating lubricating oils.

We claim: In the manufacture of lubricating oil, the

method of extracting emulsified soaps formed in neutralizin the acid bodies remaining in the oil stock a r a treatment with sul huric acid which consists in treating a su stantially sludge-free sulphuric acid-treated lubricating 011 stock with an alkaline solution, with substantially no excess solution above the quantity necessary to neutralize the acid bodies present, forming an emulsion with substantially no sedimentation, adding and intermingling therewith a finely divided adsorbent material at a temperature above 212 F., and removing from the mixture the ad'- sorbent material and adsorbed soaps by filtration.

Signed at Fillmore, in the county of Ventura, State of California, this 17th day of February, 1926.

JAMES W. WEIR. WILLIAM J. RYAN, JR. 

